Revised sping drafter



June 4, 1957 4 o. E. SANDELIN 2,794,214

REVISED SPIN DRAFTER Filed April 30; 1952 Mm:- Q INVENTOR.

OLLE E. \SHNDELIN g L Q I BY 37 3 7 2 R RIC/1E), WA Trs, soagnrolwsMSNENNY Fig. 6 V HTTOENE Y5 United States Patent 8 Swasey Company,Cleveland, Ohio, 2 carpet-cation of Ohio Application-April 30,1952',-SerialNo; 285,135 6 Claims. (Cl: 19-131) invention relates toimprovements in drafting fiber strands su'ch" as tops, slivers,r'ovin'gs; slubbin'g s', and the like; in bundles oraggregates,- all ofwhich are-re ferred to for convenience as fiber'strands'orslivers: Theinvention is particularly concernedwith' features rendering it practicalto draft crirnped staple fib 'ei's1by'draftirig heads of the type havingspaced pairs of'rol'lers nipping the fiber strand at the exit and,entrance-ends of'the'draftinjg ratch and having a higher speed'a't theexit en'd'tha'n at the entrance end ofi'the ratch. 7

An objectof the inventionis to draft crimpedxfibers uniformly andwithout causing bunching'or' flowof the fibers-in the strand. I I

Another object of the invention is. to improve-the'fiber control duringdrafting in" drafting heads. of the type mentioned with one or more airstreams.

A more specific obiect oftheinvention'is'to' improve the controlofcrim'ped synthetic fibers'fduring drafting in drafting heads of thetype mentioned by sucking; fibers of the strand' towardsamovi'nglmerhbe'r' along at-least part of'the drafting ratch so that thefibers areh'eld tip proximately stationary in relation to the'movin'gmember until they are gripped by. the .draftin'grollersatthe exit end ofthe drafting ratch.

v A'.further object is to provide'a'draftingfhead iri'which the movingmember has the form of'a' movingeridiess belt which is pervious to air;7

Still another object-is to provide a, dr'aftingjheadf in which theaction of the movingendlessair-pervioils'b elt is"suppleme'nted bysecond moving. endless. belt which .is highlyQfieXible and impervious toair.and'llies,.againstthe opposite. side of the strand from'theair-perviou's.belt}.v

An, additiona1'object-,-of the invention. isv to. provide .a nipping;action for the fibers of-fibe'r strand intermediate the entrance andjtheexit ends ofadra-ftinglatchandat. a distance from theexit endwhichrissomewhatrgreater than the average lengthof thelongest'fibersl inthe strand.

Another additionaLobject of the invention-.istoprovidea soft'nippingaction. for. the fibers of a strand which is-being held between a movingair pervious belt" and a flexible imperviousbelt. atra location close totheeexit end of a. drafting, ratch tostretch the slow moving..crirnpedfibers and to remove the crimp in the fibers.v

Other and further. objects, features andaadvanta ges of the inventionwill becomefapparen-t .from thefollowing description considered inconjunction-with the accompanying-drawings, .irrwhieh 7 Fig 1 is-an,elevation in, diagrammaticabform'rpartly insection, of. adrafting headembodying. the invention..--,

Fig. 2 is: a-fragmentaryfview-of a belt to beuseddn-the constructionotFig. 1-.

Fig. 3 isacross-sectional view. of amultiple trumpet guide employed intheapparatus-of Flgz: 1 and represented asa section cut-.bya planeS-Sindicatedin Figula- Fig. 4 is a view in perspective of thesuctionbox-ems ployedin the embodiment. of Fig... 1.

Fig. 5-lis a fragmentary cross-sectional.view-of--the*suc- "ice 2;tiohbbxolf Fig; 4 representedas cut by a plane 5-5 indicated in Fig. 1.

Figz 6 is a fragmentary cross-sectional view of a portion of'the"apparatus of Fig. 1 represented as cut by a plane 6-6. I

Like-reference characters are utilized throughout the drawing todesignate like parts. I

Referring particularly to Fig. 1 the draftinghead compri'se's a pair ofratch rolls 11-=12 mounted adjacent a itiiiltiple'trum'p'et guide 13 forreceiving a plurality of slivers'o'i' strands 14 of crimped syntheticfibers, a pair of drafting r'olls 15-16 mounted at the end of thedrafting ratch and 'an' air pervious surface member in .the' form ofabe'lt or apron 17 arrangedto have'aportion of the surface 18 thereofcontinuously traveling"ihitheidrafting ratch'; For applying suction tothe air-pervious apron 17 a suctio box 19 is provided having'a top.w'all'21' along whichthe belt 17 is adapted to travel;

lareteraumas shown, the'ratchn'ollsll and 12areof difierent'siz'e, theupper roll 11' having somewhat more than twice the diameter of the lowerroll1 2 and the'roller IZ's'eriisaloas a guide roll for the air perviousapron 173 The draftrolls 15-16 are also preferably ofun- 25 equal siie'and of difierent size from the ratch rolls 11- 12: The upperdraftingroll 1's, asshown is of nearly twice"thedia'meter' of the lowerdraft roll 16 and larger in "eter than the upper ratch roll 11. Thelower draftingr011 16 is smaller than the upper ratch'roll 11antif'appibiiiihately'twice' the diameter of the lower ra'tch roll-I2;

A drive'roli Z'Tisprovide'd for the apron or be1t17 and siii-ta'b'leamers-11s 23" are also provided. The forward edge as; or the top wan 21of the suction box: 19 is rotihded as shown'toterrn'a forward guidefor'thebeh 17.

As shownin'iFig. Zthe'belt 17 is provided with air pe'rvious-zo'n'es 24,each of which corresponds drone of the fiber-strands 14; andtheremainder 'of the belt17 is referably'iniperviou'sto air; Theair-pervio'us zone 24, as shown inFig 2 may take the form of staggeredrowsof holes ze:

The-suction box 19' has its 'top' -wall zlperforate'd to permit applyingsuction through the openings" 25'in'the b elt-fl7'and has'an exhaustco'n'ne'ction27 "adapted to be connected through a suction pipe' to an"exhaiist fan o'r vainriir-n pump; not" shown. Preferably 'the' upperwall 2130f the su'ction box-19' also has its perforations arranged inair perviouszones 28 corresponding "to theair pervieus zones 24 in thebelt17.

It hasbeen" foundthat crimped' artificial or synthetic staple fibers'present a"- greater problem in dfa fting than natiiral'fibers, whetherof 'ariii'n'alor-vegetablesource; for the-reason'that'the'surfaces ofsuch fibers normally provide 'rel'atively'little adhesion or'f'rictionaleffect and'are relatively slippery. The adhesion of 'sueh'fihers'to'each other and to the apron 17 is'prom'oted by the suction provided" bythe suction boX 19. In order to obtain the maximum degree of uniformityof the' fiberstrands, I

prefer: to provide additional fiber control at' a spacingsomewhat-greaterthan the averageleiigth at the longest fibers in'the'str'andI To this end"a'cri'mped'fiber-holding apifon nip' 'roll'or'pre'ssure roll 31 is provided iii'the draftin'g-iratcli'havingreduce'd bearing po'rtioiisdr' shafts 30 restirigin bearingblocks 32, adjustably mounted by means oflongitudinal'slots 33in sideplates 34 secfired to the top wall 210i the suction box 19 Itis to beunderstood that 'the bearingsblo'clgs' 32 are movable in one directionor anotherin the slots'33and then'secured by'suitable means suchz'asb'oltsor screws 35 so thatthe distance between the akis' o'f the101131 and the line of centers of" draft rolls 15 -16 "will exceedtheaverage'length' of the longest fibers-irrthe strand-.- The endporti'ons' of- 'th'e air=pe1-- vious zones 28 in the top wall 21 of thesuction box 19 may take the form of slots 36. The central portions ofthe air-pervious zones 28 in the suction box 19, however, are preferablyin the form of rows of holes 37 in order to minimize the sagging effectof the belt 17 and the sliver 14 held thereto by suction. The holes 37are preferably elongated or elliptical with oblique axes so as to formobliquely transverse slots or apertures.

In order to increase the effectiveness of the suction an upper surfacemember in the form of an endless belt or apron 38 is preferably alsoprovided which travels along the drafting ratch, contacting the airpermeable surface 18and the strands 14 and passing around the crimpedfiber holding roller 31 and the ratch roll 11. For guiding the front endof the belt 38 a cross strip or bar 39 is provided, which has arelatively narrow rounded nose 4.1 nipping into the space bounded by thesurfaces of the draft rolls 15-16 and an imaginary plane tangentthereto. Preferably the apron guide 39 is pivoted at the rear end on across-rod 42 and the nose 41 is resiliently pressed downward by asuitable means such as an adjustable torsion spring 43. The apron 38 iscomposed of relatively light flexible material which is impervious toair such as rubberimpregnated fabric.

Preferably the crimped fiber control or holding roller 31 is loaded,such as by weights hung from the ends of the bearing portions or shafts30, and the bearings 44 are elongated vertically. Loading may be appliedby means of bearing caps 45 adapted to be pressed downwardly by screws46 but preferably the caps 45 also have vertically elongated journalcavities in order to form a journal box which holds the journals captivebut permits vertical movement. In this manner, bunched fibers arepermitted to pass without change in pressure in apron nip or jamming.Although the invention is not limited to specific values of-pressure, ithas been found that satisfactory results may be obtained by loading thecontrol roller 31 to give a pressure of approximately 50 pounds on thefour strands 14 while the strength of the torsion spring 43 is adjustedto give a loading of about 2 pounds to the nose 41 of the apron guide39. A relatively soft fiber control or faint nip is provided at the exitend of the ratch with a pressure control in the center portion of theratch, just beyond the end of the longest fibers nipped by the draftrolls 15 16.

The nose portion 41 of the guide bar 39 gives soft control of the fibersof the four strands 14 at a location close to the nip of the draft rolls15-16 to permit fast moving fibers of the strands to slip through such afaint nip while slow moving fibers are not influenced by the movement ofthe fast running fibers.

As illustrated in Fig. the suction in the suction box tends to suck thestrands 14 against the air pervious apron 17 and causes some, saggingthereof in the longitudinal slots 36 while the apron 38 is drawndownward against the strands 14. On thesides, as at 47, air tends torush inwards between the two surface members at their edges, causing theouter edge 47 of the upper belt 38 to lie against the lower belt 17.Thus the slivers 14 are compressed into elliptical form.

At the part of the suction box 19 at which the crimped fiber holdingroller 31 rests, additional pressure is ap plied to the strand 14 by theloading of the roller 31. Sagging of the lower belt'17 is then minimizedby the fact that the air pervious zone in the top wall 21 of the suctionbox 19 consists only of relatively narrow oblique perforations 37. Thepressure roll 31, in its various adjusted positions, will have linepressure contact with the upper surface of the suction box 19 at thecentral portion thereof and bridges the rows of oblique holes therein.

The control of the strands in the drafting zone is carried out by thesuction of air which draws the thin flexible top apron 38 towards thesurface of the pervious bottom apron thus producing a frictionalresistance to the move- 4 ment of the fibers of the four strands 14passing between said aprons, and also producing a restraining action toprevent the fibers of the strands from spreading during drafting.

Additional control of the fiber strands in the drafting zone is carriedout by the action of the pressure roller on the strands at a locationintermediate the entrance and the exit ends of the drafting ratch andalso by the soft nipping action on the strands by the nose at a locationin close proximity to the exit end of the drafting ratch.

While the invention has been described as embodied in concrete form andas operating in a specific manner in accordance with the statutes itshould be understood that the invention is not limited thereto, asvarious modifications will suggest themselves to those skilled in theart without departing from the spirit of the invention.

What is claimed is:

1. In a crimped-fiber-strand drafting head of the type having a pair ofdraft rolls nipping the strand at the exit end of the drafting ratch, amember having a surface moving in a pathway along and within thedrafting ratch in a direction from the entrance and toward the exit end,and continuously contacting the strand along at least a part of thedrafting ratch, said member being formed with a row of staggered holestherein to render it air pervious therealong, a roller mounted in theratch for holding crimped fibers within the strand, a suction devicecomprising a box having a wall with an air pervious zone thereincorresponding with the air pervious zone of the air pervious surfacemember, said air pervious zone comprising slots at either end thereofand a row of perforations between said slots in the portion of said wallunder said crimped fiber holding roller, said box having an outlet to beconnected to a vacuum line.

2. In a crimped-fiber-s-trand drafting head of the type having a pair ofdraft rolls nipping the strand at the exit end of the drafting ratch, amember having a surface moving in a pathway along and within thedrafting ratch in a direction from the entrance and toward the exit end,and continuously contacting the strand along at least a part of thedrafting ratch, said member being formed with a row of staggered holestherein to render it air pervious therealong, a roller mounted in theratch for holding the crimped fibers within the strand, a suction devicecomprising a box having a wall with an air pervious zone thereincorresponding with the air pervious zone of the air pervious surfacemember, said air pervious zone comprising slots at either end thereofand a row of perforations between said slots in the portion of said wallunder said crimped fiber holding roller, said box having an outlet to beconnected to a vacuum line, a second member in the form of a belt havinga surface also moving in a pathway along and within the drafting ratch,continually contacting the fiber strand on the side opposite the firstsuch member, the second mentioned surface member being relatively thinand flexible whereby an enclosure of substantially ellipticalcross-section is formed for confining the fiber strand, said crimpedfiber holding roller mounted in the ratch and bearing upon the secondmentioned surface member for holding the crimped fibers within thestrand.

3. In a crimped-fiber-strand drafting head of the type having a pair ofdraft rolls nip-ping the strand at the exit end of the drafting ratch, amember having a surface moving in a pathway along and within thedrafting ratch in a direction from the entrance and toward the exit end,and continuously contacting the strand along at least a part of thedrafting ratch, said member being formed with a row of staggered holestherein to render it air pervious therealong, a roller mounted in theratch for holding the crimped fibers within the strand, a suction devicecomprising a box having a wall with an air pervious zone thereincorresponding with the air pervious zone of the air pervious surfacemember, said air pervious zone comprising slots at either end thereofand a row of perforations between said slots in the portion of said wallunder said crimped fiber holding roller, said box having an outlet to beconnected to a vacuum line, a second member in the form of a belt havinga surface also moving in a pathway along and within the drafting ratch,continually contacting the fiber strand on the side opposite the firstsuch member, the second mentioned surface member being relatively thinand flexible whereby an enclosure of substantially ellipticalcross-section is formed for confining the fiber strand, a guide memberextending transversely at the front end of the ratch with -a guidingnose lying within the space bounded by the cylindrical surfaces of thesaid draft rolls and the plane tangent thereto for guiding the secondsurface member and the strand well into the nip of said draft rolls,said crimped fiber holding roller mounted in the ratch and bearing uponthe second surface member for holding the crimped fibers within thestrand.

4. In a crimped-fiber-strand drafting head of the type having a pair ofdraft rolls nipping the strand at the exit end of the drafting ratch, amember having a surface moving in a pathway along and within thedrafting ratch in a direction from the entrance and toward the exit end,and continuously contacting the strand along at least a part of thedrafting ratch, said member being formed with a row of staggered holestherein to render it air pervious therealong, a roller mounted in theratch for holding the crimped fibers Within the strand, a suction devicecomprising a box having a wall with an air pervious zone thereincorresponding with the air pervious zone of the air pervious surfacemember, said air pervious zone comprising slots at either end thereofand a row of perforations between said slots in the portion of said Wallunder said crimped fiber holding roller, said box having an outlet to beconnected to a vacuum line, a second member in the form of a belt havinga surface also moving in a pathway along and within the drafting ratch,continually contacting the fiber strand on the side opposite the firstsuch member, the second mentioned surface member being relatively thinand flexible whereby an enclosure of substantially ellipticalcross-section is formed for confining the fiber strand, a guide memberextending transversely at the front end of the ratch with a guiding noselying Within the space bounded by the cylindrical surfaces of the saiddraft rolls and the plane tangent thereto for guiding the second surfacemember and the strand well into the nip of said draft rolls, the saidfront guide member having the rear end thereof secured to a spring forresiliently holding the nose of the guide member downward and providingsoft control of the crimped fiber relatively close to the rip of thedrafting rolls, said crimped fiber holding roller mounted in the ratchand bearing upon the second surface member for holding the crimpedfiber-s within the strand.

5. In a crimpedfiber-strand drafting head of the type having a pair ofdraft rolls nipping the strand at the exit end of the drafting ratch, amember having a surface moving in a pathway along and Within thedrafting ratch in a direction from the entrance and toward the exit end,and continuously contacting the strand along at least a part of thedrafting ratch, said member being formed with a row of staggered holestherein to render it air pervious therealong, a roller mounted in theratch for holding the crimped fibers Within the strand, a suction devicecomprising a box having a wall with an air pervious zone thereincorresponding with the air pervious zone of the air pervious surfacemember, said air pervious zone comprising slo-ts at either end thereofand a row of perforations between said slots in the portion of said wallunder said crimped fiber holding roller, said box having an outlet to beconnected to a vacuum line, a second member in the form of a belt havinga surface also moving in a pathway along and within the drafting ratch,continually contacting the fiber strand on the side opposite the firstsuch member,

the second mentioned surface member being relatively thin and flexiblewhereby an enclosure of substantially elliptical cross-section is formedfor confining the fiber strand, a guide member extending transversely atthe front end of the ratch with a guiding nose lying Within the spacebounded by the cylindrical surfaces of the said draft rolls and theplane tangent thereto for guiding the second surface member and thestrand well into the nip of said draft rolls, the said front guidemember having the rear end thereof secured to a spring for resilientlyholding the nose of the guide member downward and providing soft controlof the crimped fiber relatively close to the nip of the drafting rolls,said crimped fiber holding roller mounted in the ratch and bearing uponthe second surface member for holding the crimped fibers within thestrand, and means for holding the crimped fiber holding roller with apressure substantially greater than that of the guiding member for thesecond surface member.

-6. In a crimped-fiber-strand drafting head of the type having a pair ofdraft rolls nipping the strand at the exit end of the drafting ratch, amember having a surface moving in a pathway along and Within thedrafting ratch in a direction from the entrance and toward the exit end,and continuously contacting the strand along at least a part of thedrafting ratch, said member being formed with a row of staggered holestherein to render it air pervious therealong, a roller mounted in theratch for holding the crimped fibers within the strand, a suction devicecomprising a box having a wall withan air pervious zone thereincorresponding with the air pervious zone of the air pervious surfacemember, said air pervio-us zone comprising slots at either end thereofand a row of perforations between said slots in the portion of said wallunder said crimped fiber holding roller, said box having an outlet to beconnected to a vacuum line, a second member in the form of a belt havinga surface also moving in a pathway along and within the drafting ratch,continually contacting the fiber strand on the side opposite the firstsuch member, the second mentioned surface member being relatively thinand flexible whereby an enclosure of substantially ellipticalcross-section is formed for confining the fiber strand, a guide memberextending transversely at the front end of the ratch with a guiding noselying within the space bounded by the cylindrical surfaces of the saiddraft rolls and the plane tangent thereto for guiding the second surfacemember and the strand Well into the nip of said draft rolls, the saidfront guide member having the rear end thereof secured to a spring forresiliently holding the nose of the guide member downward and providingsoft control of the crimped fiber relatively close to the nip of thedrafting rolls, said crimped fiber holding roller mounted in the ratchand bearing upon the second surface member for holding the crimpedfibers within the strand, means for holding the said crimped fiberholding roller with a pressure substantially greater than that of theguiding member for a second surface member, and slotted members oneither side of the perforated wall of the suction box for adjustablysupporting the crimped fiber holding roller to enable it to be spacedfrom the nip of the draft rolls a distance as great as the averagelength of the longest fiber of the strand of crimped fibers.

References Cited in the file of this patent UNITED STATES PATENTS109,430 'Leavitt Nov. 22, 1870 2,219,356 Dreyfus et al. Oct. 29, 19402,231,526 Casablancas Feb. 11, 1941 2,306,848 Toenniessen Dec. 29, 19422,659,936 'Sandelin Nov. 24, 1953 FOREIGN PATENTS 974,412 France Feb.11, 1951

